Nguyen Van Nhat, Nguyen Quoc Manh, Huang Shyh-Chour
Department of Mechanical Engineering, National Kaohsiung University of Science and Technology, 415, Chien-Kung Road, Sanmin District, Kaohsiung 80778, Taiwan.
Department of Mechanical Engineering, Hung Yen University of Technology and Education (UTEHY), Khoai Chau 39000, Hung Yen, Vietnam.
Materials (Basel). 2018 Jul 4;11(7):1136. doi: 10.3390/ma11071136.
The tungsten inert gas (TIG) welding method most commonly used to weld ferrous metals, nonferrous metals, and other metals since it is simple, easily implemented, and achieves consistent high-quality welds. In this study, butt joints produced between aluminum alloy A6061-T6 and stainless steel SUS304L have been achieved by using TIG welding with ER4047 filler metal. The macrostructure and microstructure of the resulting specimens were analyzed by means of an optical microscope (OM), a scanning electron microscope (SEM), and an energy dispersive X-ray spectrometer (EDS). A uniform intermetallic layer was found at the interface between the stainless steel and the weld seam having a thickness of 2 µm, and the intermetallic compound (IMC) includes Fe₄Al, Fe₂Al₅, and FeAl₃ phases. The micro-hardness and tensile strength of the weld joints were also investigated. Due to Si content in the compensating metal, there was a prevention of iron diffusion into the aluminum, thus hindering the development of the IMC layer and reducing its thickness in such a way that the weld joint strength increases. The analyzed results show that the average micro-hardness of the stainless steel, weld seam, aluminum alloys, and IMC layer were 218 HV, 88.3 HV, 63.3 HV, and 411 HV, respectively. The fracture occurred at the brazed interface, and the ultimate tensile strength value reached 225 MPa.
钨极惰性气体保护（TIG）焊接方法是焊接黑色金属、有色金属及其他金属时最常用的方法，因为它操作简单、易于实施，并且能实现始终如一的高质量焊接。在本研究中，采用ER4047填充金属的TIG焊接方法实现了铝合金A6061-T6与不锈钢SUS304L之间的对接接头。通过光学显微镜（OM）、扫描电子显微镜（SEM）和能量色散X射线光谱仪（EDS）对所得试样的宏观结构和微观结构进行了分析。在不锈钢与焊缝的界面处发现了一层均匀的金属间化合物层，其厚度为2μm，金属间化合物（IMC）包括Fe₄Al、Fe₂Al₅和FeAl₃相。还对接头的显微硬度和拉伸强度进行了研究。由于补偿金属中的硅含量，防止了铁扩散到铝中，从而阻碍了IMC层的生长并减小了其厚度，使得接头强度提高。分析结果表明，不锈钢、焊缝、铝合金和IMC层的平均显微硬度分别为218 HV、88.3 HV、63.3 HV和411 HV。断裂发生在钎焊界面处，极限抗拉强度值达到225 MPa。
